From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mout-p-101.mailbox.org (mout-p-101.mailbox.org [80.241.56.151]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 8DC205012B2; Mon, 28 Sep 2026 21:32:46 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=80.241.56.151 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1790631170; cv=none; b=VjxsHQQfygZeyVJVpEBS2rIoCPsjtA8hX8WSBakE0yMS3Rrp6fkgxusHEiBQ0PbQgV2Kl8oUpreccSvkW5fbXsXp/CViMN002uq8jr77iAKONgGPfrkpsHi5HC5mlJwTrm9DKoT6DKDEnk7X4m0r/OV+VVY3FEhBEdosuHqJJMg= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1790631170; c=relaxed/simple; bh=epNoroeavcGYBU0gF0l4Ccj9MVBTx/Y5ypuGkTvRQp4=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From: In-Reply-To:Content-Type; b=es5Vu3FR909wG2iPnaUXNGCR32WVJ8rCtWN+GH/Le4IWHyhPgjuEGht5DBjlPMjIC0tdcRqUNSAsUJN97lTwpGQkMctWhfyx2cbj39bdFlJ/yjmCrqo2+Syww4RputEr/XYv5rMeq5IB32CQECRTQYzD2E7HtECkMQOZcxIeNGE= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=mailbox.org; spf=pass smtp.mailfrom=mailbox.org; dkim=pass (2048-bit key) header.d=mailbox.org header.i=@mailbox.org header.b=jkF+kUhs; arc=none smtp.client-ip=80.241.56.151 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=mailbox.org Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=mailbox.org Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=mailbox.org header.i=@mailbox.org header.b="jkF+kUhs" Received: from smtp2.mailbox.org (smtp2.mailbox.org [IPv6:2001:67c:2050:b231:465::2]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange x25519 server-signature RSA-PSS (4096 bits) server-digest SHA256) (No client certificate requested) by mout-p-101.mailbox.org (Postfix) with ESMTPS id 4htvfd18H1z8vVc; Mon, 28 Sep 2026 23:32:41 +0200 (CEST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=mailbox.org; s=mail20150812; t=1790631161; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=rXP4kntCRSr0u9GLCjjrcHN16qzZLRh3uXI4VNGJVtc=; b=jkF+kUhsNBuDQ8l1B8GovLmQ2G6gJbB/kajiYp380+se5g6+slhn1RnbbaEK0kalnCNQl/ +Tc8KmRNwZSYanK95gQA+PimSycl4X7zo3uEJ0DiCkxhmvxen8VqngSzgmkykjEWXDPvWg cBw0IWxlw73q9aDl1wTk5D5Hfx68voqpQ1hF7EPnOHXjmrNdX3BKJjmRm/bMzvnrF1f5J8 vx3ftHeM43gST5ayX/k/pdmxVh1/ahl1SI+vtOMbmDOFSXGGIWRyk6tHonljMyjerFx0S5 8YZz4VRzjUKop0+pg2SK8UZc6HroFLBQmITGvK0uzpvLfXPcgVDr+wiP76RXfA== Message-ID: <3bb47958-09e2-4726-85e3-8e5d3873840e@mailbox.org> Date: Mon, 28 Sep 2026 23:32:37 +0200 Precedence: bulk X-Mailing-List: devicetree@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH v5 6/6] PCI: dwc: rcar-gen4: Add support for R-Car X5H PCIe4 To: Bjorn Helgaas Cc: linux-pci@vger.kernel.org, =?UTF-8?Q?Krzysztof_Wilczy=C5=84ski?= , Bjorn Helgaas , Conor Dooley , Geert Uytterhoeven , Krzysztof Kozlowski , Lorenzo Pieralisi , Manivannan Sadhasivam , Rob Herring , Yoshihiro Shimoda , devicetree@vger.kernel.org, linux-kernel@vger.kernel.org, linux-renesas-soc@vger.kernel.org References: <20260928210155.GA2260978@bhelgaas> Content-Language: en-US From: Marek Vasut In-Reply-To: <20260928210155.GA2260978@bhelgaas> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit X-MBO-RS-META: w9fowsmy3hfd6ozkkg67j5hakjag8bcx X-MBO-RS-ID: 2656e4effd21e824bcb On 9/28/26 11:01 PM, Bjorn Helgaas wrote: > On Mon, Sep 21, 2026 at 10:27:48PM +0200, Marek Vasut wrote: >> Add support for R8A78000 (R-Car X5H) PCIe4. >> >> This driver previously supported R-Car Gen4 S4/V4H/V4M. PCIe features >> of R-Car X5H PCIe4 are almost all the same. >> >> The controller initialization sequence is slightly different and is >> factored out into controller specific callbacks, in a manner similar >> to previous R-Car Gen4 handling. >> >> The controller does have a PHY attached to it, but the PHY is operated >> by a separate PHY driver, the PHY driver instance binding is handled >> in rcar_gen4_pcie_get_resources() and controlled in the aforementioned >> controller specific callbacks. >> >> The controller driver is deliberately using "renesas,rcar-gen5-pcie4" >> DT compatible string to discern R-Car X5H PCIe4 controller supported >> by this driver, from R-Car X5H PCIe6 controller which will most likely >> use a separate driver. > > The gen5/pcie4 usage is confusing. > > I often push back on things like "PCIe Gen4" because it's ambiguous > (does it mean "compliant with base spec r4.0" or "supports 16 GT/s" or > something else), but it's so widely used to mean transfer rate that > it's hard to resist, and the best I can hope for is clarification. > > But in "renesas,rcar-gen5-pcie4", I don't know what the 5 and the 4 > mean. Maybe "gen5" refers to some internal R-Car thing, and "pcie4" > is something like "PCIe Gen4, i.e., 16 GT/s"? Gen5 refers to R-Car Gen5 (5th R-Car SoC generation). PCIe4 refers to the PCIe Gen4 core in the R-Car Gen5 SoC. There is also PCIe Gen6 core in the same SoC, but that will require a different driver and different compatible string. Since none of this shipped in any kernel version yet, would you prefer some sort of rename ? I can send patches. -- Best regards, Marek Vasut